Application of MSCAP to a fusion reactor superconducting magnet system with an internal short

The Fusion Safety Program of EGandG Idaho, Inc. at the Idaho National Engineering Laboratory (INEL) is developing a safety analysis code called MSCAP (Magnetic System Circuitry Analysis Program) to evaluate electrical circuit responses in large magnetic systems, such as those in tokamak and mirror-type fusion reactors, under normal and off-normal conditions. MSCAP is an electrical analysis code designed to handle fast response transients such as those resulting from circuit breaker action and internal magnet shorts and arcs. Because of the large amount of stored energy in these magnetic systems, electrical protection circuitry must be incorporated to respond adequately to these types of accident conditions. Analysis capability of accident responses, especially those arising from electrical shorts in magnets, can reveal inherent design limitations and areas of important safety concerns. MSCAP has been used to study the effects of an assumed electrical short across one, three, and five turns of a 444-turn magnet during fast and slow electrical system discharge transients of a large superconducting tokamak system